Henry elliott



(No Model.)

H. ELLIOTT.

LOOK. No. 465,974. Patented Dec. 29, 1891.

NITED STATES PATENT OFFICE.

HENRY ELLIOTT, OF LOS ANGELES, CALIFORNIA.

SPECIFICATION forming part of Letters Patent No. 465,974, dated December 29, 1891. Application filed April 15, 1891. Serial No. 389,017. (No model.)

T0 at whom it may concern.-

Be it known that I, HENRY ELLIOTT, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Multiple Key-Lock, of which the following is a specification.

The object of my invention is to provide means whereby the person having primary control of a room or other inclosure can allow a lessee or other person to have joint access thereto while excluding others, and can at plea-sure prevent such other person from gaining access.-

- A further object is to provide means whereby an ordinary door-lock can be made proof against pass or skeleton keys.

My invention comprises a lock having its bolt provided with a series of dissimilar keyreceiving notches so arranged with relation to the key-hole that the bolt may be successively advanced or retracted by a series of dissimilar keys applied in rotation in said key-hole. v

The accompanying drawings illustate my invention. 4

Figure 1 shows the interior of the lock with the bolt in its withdrawn position ready to be driven forward by the first key of the series. Fig. 2 shows the lock with the bolt projected to its first locked position and ready to be withdrawn by the first key of the series or to be further advanced by the second key of the series. Fig. 3 shows the lock with the bolt fully advanced by the second key of the series and in position to be retracted by such second key. Fig. 4 shows a portion of the lock in cross-section with the first key of the series inserted and turned to engage the bolt and dog. Fig. 5 shows a portion of the lock in cross-section with the second key of the series inserted and turned to engage the bolt and dog.

A is a bolt provided with a series of two key-receiving notches B O, unlike in depth.

D is the dog, provided with a series of boltretaining lugs E F, arranged to engage the bolt-pin or lug G, which normally restsin the notches a b c, which are arranged to receive it when the dog is at rest.

H H are the keys.

To economize space I chamber the bolt with the recess I to receive the end of the dog and its spring J when the bolt is retracted.

perior degree of security results from my im- In practice it is designed for the landlord or other principal to retain one each of the keys H and H, while the tenant or other one having secondary rights is given the first key H of the series. Thus the landlord and tenant each have control over the look so long as the first key only is applied in fastening the lock.

Incase the tenant fails to settle his bill, or if for any other reason it-should be desired to exclude him from his room, the second key H of the series is applied to further advance the bolt to the position shown in Fig. 3, and then the first key H becomes useless until the second key H is applied to again throw the bolt into the position shown in Fig. 2.

L represents one wall of the case of the lock provided with the key-hole M.

The two keys in my improved lock are complementary to each other, as will be seen by comparison of Figs. 4 and 5-that is to say, the ends of the blades of the two keys would fit each other if set point to point. For this reason when the lock has been locked with the two keys it cannot be unlocked by a less number of keys, for the key necessary to move it from its third position to its second is the direct opposite of that necessary to move it from its second position to its first or unlocked position. I have found in practice that this necessitates exact construction upon the part of both such keys, so that a suprovement, making it impossible, so far as I am aware, to pick the lock or unlock it without the proper keys, a hair-breadth of error being sufficient to prevent the key from operating.

Now having described my invention, what I claim as new, and desire to secure by Letters Patent, is

A look provided with two dissimilar keys and with a bolt having two dissimilar key-' receiving notches, whereby the second key is adapted to engage the bolt and move it forward a distance after the first key has moved the bolt the usual distance, thus causing the first key to be inoperative until the second key is used to partially return the bolt.

. HENRY ELLIOTT.

Witnesses:

JAMES R. TOWNSEND, ALFRED I. TOWNSEND. 

